1. Field of the Invention
The invention relates to an implantable biodegradable system for releasing active substance.
2. Description of the Prior Art
Numerous implantable or injectable systems for releasing active substance are known from the prior art. Systems of this kind are preferably used when an active substance has to be administered over a fairly long period of time and oral administration is impossible or unreliable or impractical. In addition to use in humans, parenteral preparations for use in animal husbandry or for the treatment of animal diseases are of special interest. The conventional method of administering drugs by adding them to the feed has the serious disadvantage that the quantity of drug taken is not sufficiently accurate.
Implantable systems for releasing active substance should satisfy the following criteria:
The active substance should be released over a long period of time at a constant rate, the implant should be broken down within a reasonable interval so that there is no need to remove the implant by operating after the active substance has been released. It is also advantageous if the release of active substance from the carrier can be made variable so that the rate of release can be matched both to the active substance and also to the particular treatment.